here are several main types and models of cloud-based testing tools and services you need to examine in order to choose the one that suits you best:
Tenancy mode — A cloud-based testing solution can be single- or multi-tenant, which means it provides access to one instance to one or several clients. Using shared multi-tenant testing solutions is usually more affordable than using isolated ones. But an isolated solution can ensure a higher level of security, which is important if you’re working with sensitive data.
Deployment type — There are three options to deploy an application for cloud-based testing: public, private, or hybrid deployment. Deploying on a public server is the most popular option that provides resilience and ease of deployment. Using private and hybrid testing environments is more secure, but these environments are also trickier to configure. Also, not all cloud-based testing tools provide private deployment possibilities.
Service model — As with any cloud computing service, testing solutions come in the form of Software as a Service, Platform as a Service, and Infrastructure as a Service (SaaS, PaaS, and IaaS) models. These models provide you with different levels of responsibility for, control over, and maintenance obligations related to your testing solution.
In addition, cloud-based testing has given rise to Testing as a Service (TaaS), which allows organizations to outsource their testing efforts. TaaS can be used for overall software testing as well as for conducting specialized types of testing such as performance, security, or functional testing.